Telephone-exchange system.



` F. A. LUNDQUIST. VTELEPHONE EXCHANGE SYSTEM. Armcmou mio ngc. 2.1916.

Patented Jan. 8, 1918.

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F. A. LLINDQ'UIST.l TELEPHONE EXCHANGE SYSTEM;`

Armcmou msu ngc. 2. nys.

- y Rim? i UNITED' STATES PATENT oFFIoE.

EEA'NK'A. LUNDQUrsT, '0E' NEW Yoan,- N. ryassIeNoa To wEsTEEN ELECTEIC Com- PANY, INCORPORATED, or NEW Yemen. Y., A CORPORATION or NEW Yonx.

TELEPHONE-EXCHANGE SYSTEM.

' Specification of Letten Patent.

Patented Jan. s, 191s.

Application ill-ed December 2, 1816. serlal No. 134,572,

To .all inkom they concern a citizen of the United States, residing at New York, in the county of .NewYork and State of New... York,` liave 'invented certain newl and' useful ,Improvements in Telephone-@ Eehange Systems,j 015 which the following is .ak fn'll, clear,-concise, and exact descr1ption. i 1

This invention 4relates. to telephone exchange systems, and has for its object a provision of means whereby the capacity 'of an automatic telephone systememay be greatly increased without making the called numbeis iised therein unmanageable. n

Suchen object maybe aceomplishedby using 4impulse senders` of ,greater capacity than ut present, whereby each digitof'll heleplionelvnumbermaybe selectedm a greater number of. ways than at present, andV by uSngnseleetive switches of 'correspondingly increasedrcapacity. A. u .1.

l A eatuie of; his; `inventionis yan impulse transmitter having afplurality4 of--hset's vof positions, whereby` the same trainof.; impulses.

iriay` betransinitted from --correspoiiding positions in each of. said-sets of positions.

This impulse transmitter is also provided with a circuit chan ing, devlce whereby a ,differenti circuit ,conyition isset up in connectiongfwith each diierent set of. positions to cliaracterize'such. sets of positions,l andV differently effect` the apparatus intended to,

receivesuch ylllfipnlses. e Another teature `of this inventionisa se- 'activ'e switch-:arranged vto v serve a4 plurality of groups of. linesiin' which the terminals of one group `are,periodically interspersed between lthe terminalsef other '.groups` Still,anotlier .feature of4 this Invention is the: use ottivo lne-re'lavs, one otwhicli is marginal. The combined action ot these two relays isthe same. during thesendingofimp u1ses..froin allpositions of the impulse transmitter-,ibut is.diii'erent during the s et ting ofsuch, impulsetransniitter in the dif-.i

grolipiof lines-,inwhich the' connection is esired is automatic-ally selected.'

The drawings disclose this invention 1n the form of a complete automatic teleplione understood r y q i l system including in Figure 1 a calling sub- Be it knowmthat I, F RANK A. LUNDQUisr,

sc1" iber"s substation and a selector switch, and in Fig. 2 a connector switch and a called' subscribers substation, all shown diagrammat-ieally.

Itv is thou ht the invention may best be om the following detailed description of aV complete cycle of actions in interconnecting -tWo subscribers substations. In Fi 1 a subscribers substation S1 is shown. n series with the line conductors of such a substation is an impulse transmitter I, whichis arran ed to send ten different series of impulses rom two different sets of positions. In one set of positions impulses designatedby the numerals 1 Vto 0 inclusive, may be sent, and in anotheii set ci positions impulses designated b4 the letters A to J inclusive, may be sent.- sent, frio p' the ostion desi Vated by the numerlV are t Ve same as t ose sent from the position ,designated by the letter A, etc.

In one case, however, th'esubscribers fingerV While setting such an impulse transmitter comes in contact with the st'op @,and inthe other case comes first in contact with the` l knovvn type.4 Itis to be understood that theA contact 1 is only opened while the ,impulse transmiter is being set and that through lthe y actual sending of the impulses such contact,

is closed. l.

Let it be assumed .thatthelsiibscriberfati, substation Si has removed Vhis receiver from.

its hookand that the call has been extended inlany well-known manner to the selector switch SS. A circuit is thereupon. established from ground, battery, the'mwin'dngof relay 5, first position contact and'idewitch.

arm 6-the lower limb `of the'te/le" honeline leading to the subscriberswsubstat on 81,111@

contaetr, the contact-1, the transmitting i apparatus of the subscribe/Ns substation- S the upper limb of the telephone line, the side-switch arm 7 and its 'st posit-ion contact, the winding ofrelay 8, to ground. The

relays 5 and 8 are energized in this circuit and as a result another circuit is established from ground, battery, the ma net Rel.1, alternate contact and right-han armature of relay 5, to, ground, through which this magnet is energized.

The release magnet Rel.1, upon attracting its armatures, allows the cams 9 and 10 to make physical contact with the notches of the vertical and rotary ratchets in such a manner as to prevent the switch from releasing from any set position.

At thesa'me time a circuit is established from the ground, the upper pair of contacts 11 actuated by the magnet Rel.1, conductor 12, thence through the test wire of a line switch (not shown) to Well-known apparatus therein to prevent the release of such line switch.

The brushes 51, b2 and b secured to the shaft 13 of this selector switch are arranged to travel over and make contact with the terminals 1, t2 and t1 respectively. Such terminals are arranged in twenty levels of ten contacts each, the even numbered levels of such contacts leading to one group of lines and the odd numbered levels of such cievatedftwo levels of such termina s upon each .ener ization of the primary magnet PM1, soutat from the normal position the first ,energization of such primary magnet will bring the brushes in association with the first Vlevelof the contacts and each subsequent .energization will bring the brushes in associa-tion `with each succeeding odd numbered level.

If, however, the magnet 14 is energized previous to the energization of the magnet PMl the brushes b1, b2 and b3 will be elevated one Vstep only, and, upon the first energization of the ma net PM1', the brushes b1, 52- and b3 will be rought into association with the second .level of terminals t1, t2 and t?, and each subsequent energization of the magnet PM1 will elevate these brushes to a successive even numbered level of terminals.

Let it be assumed now that the sub scribers, substation S1 on the first setting of the impulse transmitter I chooses the :let-

ter E. Upon so setting this imp ulse transmitter, the subscribers finger coming 1n contact with the tripper t introduces the resistance 2 in the line circuit. Relay 8 is marginal, and due to the decreased current flow resulting from the opening of the contacts 1 denergizesf but relay 5 still retains its energized position. A circuit is thereupon established from ground to the contact and armature of relay 8, the left-hand armature and contactof relay l5, the vertical off-normal switch V.O,N., the windingA of magnet 14, to battery and round. The magnet '14 vis'.energze d andeevates the shaft Y11 so -v Idesired level of terminals.

openings of the line circuit whereby both relays 5 and 8 are intermittently denergized and cause their armatures to vibrate rapidly. The magnet Rel.1 being slow to release is not affected bythe intermittent break in its energizing circuit.

Upon each retraction of its armatures by relay 5 a circuit is established from ground, the right-hand armature and 'normal contact .of relay 5, the contacts 15 actuated by the magnet Rel.1, the magnet PM1, the first position contact and side-switch arm 16, the magnet Escl, to battery, and ground. Magnet PM1 responds to each impulse and'thereby elevates the brushes b1, b2 and b3 to the The magnet Esc.1, however, is energized by the first impulse and remains so energized until the last impulse has been received. Upon its deenerzation the side switch is escaped into the cond position.

In the second position of the side switch a' circuit is established between ground, .the contact and armature of magnet Esc.1, rotary off-normal switch R.O.N.1, side-switch wiper 17 and. its second position contact, vwinding of magnet 18, to battery and ground.. The magnet 18 is energized in this circuit and completes another circuit from ground, armature and contact of relay 18, Contact 15, winding of magnet SM1, armature and contact of magnet SM1, second position contact and side-switch arm 16, winding of magnet Esc.1, to battery, and ground. Magnets SM1 and Esc.1 are energized in this circuit. The magnet SM1, how.: ever, attracts its armature and opens its own energizing circuit and in this well-known manner causes the rota-ry movement of the brushes 61,52 and 71H. At the end of the rst rotary step a rotary off-normal' contact R.O.N.1 is opened andrela'y 18 depends for its energizatron upon circuit extending from ground, battery. winding of magnet 18, the second position contact and sideswitch wiper 17, the brush b1, the terminals t1, to the ground in the circuit of busy connector switches, in a manner to be described somefv what later. When the brush b1 in its rotary movement encounters' the terminal t1V olgwhich there is no ground, relay 18 isl fdfe energized and in turn the circuits for magi? nets SM1 and Esc.1 are opened, whereuprr ioo Vxfseaaes both of these magnets will retract their armatures. i

The retraction of its armature by the magnet Esc.L escapes the side-switch wipers into the third position whereupon a circuit is established from ground, battery, the magnet Rel, the third position contact. and sideswitch wiper 17, the brush b1', the terminal t1, and thence to ground which is placed thereon within the circuit of the seized connector switch before the magnet Rel. can retract its armatures, in a manner also to bc described somewhat later.

The movement of the side-switch wipers 6 and 7 into their third positions extends the line conductors fromthe subscribers substation S1 through'the brushes b2 und o, terminals t and t','xto the talking conductors of the connector switch CS. At the same time the control of the relays 5 and 8 is removed from the Line and control of a similar pair of relays 20 and 21 .is substituted. The immediate ener ization of relay 20 establishes a circuit rom ground, the right-hand armature and alternate contactof relay 20, the side-switch wiper'22 in its first position, the conductor 23, the winding of magnet Rel?, to battery and ground. The connector switch release magnet is energized in this circuit and establishes another circ it 'for controllingt-he release of the selector switch S51 from ground, the left-hand armature and contact of magnet Rel?, the terminal t1. the brush b1, and thence over the circuit previously described.

Let it be assumed in this case that the position of the impulse transmitter selected 'by the subscriber at the substation S1 is that designated b'y the numeral 5. In this ease the tripper t willy not be touched aml the contacts l will, therefore, not be actuated: in turn the relay 21 will remain energized and the circuit, which would otherwise be completed to energize the relay 24 similar in construction and action to relay 14, would not be energized. Upon the receipt of the five impulses sent by the impulse transmitter armatures of relays 2() and 2L will vibrate rapidly. 1'

'liherelease magnet in this case, as before, is 4slows-to .release and will not., therefore, be 'atfectedl'iy the short`breaksin its energizing circuit. During these breaks a circuit will be established from ground, right-hund armature and normal contactof relay 20, the right-hand armatru'e and contact of relay Rel t, lthe.'winding of magnet PM2,V the first position contact. and side-switch wiper 25, the win( ing of magnetV Est-.2 to battery. and ground. Through the actuation of the primar /fma net the brushes 7;* o andy b are dri/ven in o association with the fifth odd lnmnbered, or ninth level of terminals t". t5

87. lt shouldibe noti-ed at hthis point that the connector switch is provided with terminal' sets leading to four hundred lines. arranged in twenty levels ot' twenty sets ol" contacts each, and that the terminals of one group ol' Va. hundred lines are pcriialically interspersed between the' terminals of the other three groups of one hundred linesl cach in a Illanner similar to that heretofore described.

At the end of this serie,l of impulses the escape magnet llsc.2 deinergizes and causes the movement of, the side-switch wipers of the connector CS to move into the second position:

Let it be assumed now that the suliscriber at substation S1 actuates the impulse transmitter from the position designated by the letter (fr. ln this case, as in that. first'described, thel contacts 1 will-be-opcned in a manner `similar to`the previous case. The relay 21 will retract'ts armatures but relay 2() will not. circuit is thereupon estalilished from ground, contact of relay 2l. the lett-hand armature and contact of relay 2t). the side-switch wiper 2li and its secoml-posi- `tion contact. the rotary olf-,normal switch PJLNP, the windingot' magnet 27, to battery and ground. 4l`he magnet :2T is cuerg'ized in. this circuit and actuales a. pawl similar in constructionJQ.that actuated by the p'nlgncthM1 to drive the 'shaft of the connector switch lone rotary step.

lt ,slrould be noted in this caso that the secojdry magnet' SM2, like the primary ma;` ie s PM* and PM?. s-adjusled to drive the brushes over two sets of terminals at, each step` so that no'\\' ivhen the impulses from thc-impulse transmitter l are i-'eceivetL the consequent intermittent cmwgization of this magnet SMe rotates the brushes into the seventh evcn` or fourteenth rotary positornof, such brushes.

Should thtI line now engaged by the brushes o". r" and o" be busy. such condition will` bc determined by the presence of a ground potential on the terminal f". whereby a circuit wi|l ,be established from ground, terminal t", brush b, side-switch wiper 28 and its secoml position contact` winding of relay '25). tobattery andground. ltelay 29 attracts its urli/a yure 4and establishes` a. cilcuit from groun'. the secondary ot transformer 'l`,'th`e,*.u nature and contact of rclay 2f), the winding of magnet Esc?, to bat.- tery. and ground. whereby this escape' magnet is prevented. lfrom moving the sidcswitch 'wipers "nto the third position. 'lhrough the nudi-linking of theprimary and the secondary windings of the transformer a. busy tone is induced in thc circuit extending from ground, secondary of transformer T. the arma ture and contact of relay 29, the condenser C, the second position contact. .md side-switch wiper 30, the upperlmature.` alulconlact of relay El?, and i susl talkin conductors of the connector switch CS, se cctor switch SS and the subscribers substation S1, whereupon the 'subscriber is infomed of the busy condition of the desired line.

On 'the other hand, should the called line be idle, the escape magnet Esc.2 will more the side-switch wipersinto thev third position, whereupon a lcircuit will be established from ground, the right-hand armature and alternate contact of relay 2Q, the side-switch wiper 22 and its third position' contact, the conductor 34, the armature and contact of tripping relay 35, the normal contact and right-hand armature of relay 36, toa point where the circuit divides, leading in one direction through the winding of relay-32 to battery and ground, and in the other direction through' the contact-l and left-hand armature of relay 36 to the winding of relay Rel.2 to battery and ground. Relay Rel. is retained in its energized condition and relay 32 is`energized in this circuit, whereupon th'e-'called subscribers telephone bell is rung through a cir'cuit from a source of ringing current, the left-hand windingr ofv relay 35,' the alternate contact and inner armature of relay 32, side-switch 'per 31 in its third position the brush b5 an vterminal t5, the called subscribers telephone bell, the terminal t, the brush b, the third position contact and side-switch' wiper 30, the outer armatureand alternate contact of relay 32 the right-hand winding` of tripping relay 35 to the other po'le of the source of ringingcurrent. I Y

When the subscriber at substation S2 in answer to the summons of-'his telephone bell removes his receiver from its hook, he places a path of such low resistance in the circuit just describedthat the current, which heretofore was not great enough to energize the relay 35, now becomes sufficient for this purpose, and relay-35is energized; ,In attract.-

mg its armature, .rela 35 removes a short .circuit existing aroun .the winding of relay 36 and consisting of a path from one side of this winding through theV armature and contact o'f. relay 35 -'and the normal contact and armature of relay 36 to the other side of this winding, and thereby places the \'vinding of relay 365 inscreswith the winding of relay 32. Relay 36 is energized in this circuit and attracts .itsarmatnrem setting up for 'itself batter alternate ,Contact and right-hand' armature of relay 36, the winding ,of relay.

its armatures f ,dutors of the connector switch CS tgrough es 2.

a locking circuit extending from ground,

36, conductor 34, the third position contact and sidelswitch wiper 22, the Aalternate 4conright-hand armature of relay 20, to

groun The relay '32 is s hunted by this circult and denergizeswhereupon .it retracts and extends ,the talking conto; the called subscri-bers substation contact and inner armature of relay 32, sideswitch wiper 31 and its third position contact, brush 7), terminal t, through the ap-y paratus and called subscriber-s substation, terminal t, brush b, third position contact and side-switch' wiper 30, outer armature' and normalcontact of the relay32, the upper limb of the talking circuit, the left-hand winding of relay 37, tolground. The relay 37 attracts its armature and completes aeir'-x cuit from ground, the right-hand-,armature and alternate contact of relay 20, the sideswitch wiper 22 in its third position, armature and contact of'relay 37, the conductor 23, release magnet Rel?, to battery and. ground.

It should be noted that the' circuit for the energizing of release magnet Rel.2 was opened for a very short space of time during the interaction of the relays 35, 36 and 32, but relay Rel.2 being slow to release did not retract its armatures before its energizing Circuit 'was again. completed by the action o'E relay 37. A

4Upon the .movement of the sidesw-itch*` wiper 28 into its third position, a ground was coV nected to the brush b to characterize th ieized line thereafter as busy, and atthe s me time to actuate the usual cut-ott` relay connected with such a line. f

'It willl be noted that the control o'jf the connection'A new vresides in both subscribers, for, should either hang 11p-their receivers, the last described circuit for the energ'i'zation of release magnet Rel.2 will be opened at either. one or the other of the two hpoints controlled by the calling or called subscribers respectively.

Let it`be assumed in this case, that, when the conversation h as been completed', vthe calling subscriber hangs up at practically the same time as the called subscriber lThe energizing circuit for release magnet Rel.z will, therefore, be o cned both at the 'alternate contact and riglit-hand armature .of rei' la'y 20 and at the contact and armature of re lay 37. The connector switch GS' will be restored to its normal position 'andthe r'emoval of ground' from the terminal t1., due4 to the retraction of its left-hand armature by the relay Rel.2 will result in the denergization of the magnet Rel.Jl of thes'elector switch SS, whereby this Selector switch will also be restored to its normal position..

It should be` noted in this type of switch, in which the release is accomlilishedby a backward rotar.y movement and then a downward vertical movement, that at the end of the rotary movement ,the arcta-ry offnormal switch RUN,1 is closed and the l side-switch wipers are not restored to their normal position until the completion of the vertical restoring movement. However, ,t when the side-switch wipers were originally contact. of side-switch wiper 16, windin of magnet Esc.1,fto battery, and groun whereby side-switch wipers are lfinally restored `to their original position. Therefore, when at-` the end "of the rotary, restoring,` movement the switch RON?` is closed, the ground at the armature and contactof relay Escis prevented from reaching the winding of` magnet Rel, which would thereby prevent the proper release of this switch.

Whilezthis invention .has been described in connection with a full :automatic telephone system it is not to be limited to such ausystein, but, since it may be appliedwithiA equal advantage to systems of-other .typesy` `is to be limited only by the appended claims. p

What is claimed is: y K 1. In a telephone system, groups lof tele. phone lines, multifgroup selectivev switches senders forsetting said switches, a circuit g meansfor sai I "circuit changing Vdevice 'for causing saidy brushes to` be set on` terminals ofl a selectedy phone lines, multgroup'lselective switches arranged to interconnect said lines, line terv 'minals in said.` switches, the terminals of, a` group of lines being periodically interchanging device in said senders arranged to be operative'only while said senderisbeing set in certainswitches" responsive to said groulipflines.y z i ,e

2. a telephone system, groups of. telespersed between the terminals of other groups oflines, a set of brushes in each of said switches arranged to' travel over and make contact with said terminals, and imulse senders arranged while being set to sirect said brushes to a particular group ot line terminalmnnd while operating `to direct said brushes to wprticular set of terminals in said selected group.

3. In a telephone system, groups'of teley phone' lines, multi-group selective switches or interconnecting saidlines, line terminals in saidswitchesj, the' terminals of aigroup of lines Vbeing periodically interspersed between the terminals of other roups of lines, a set of brushes in each cfg said switches arranged to travel over and make contact round, thev right-hand armature` and' Vnorma contact of relay 5, the third` position this magnet is energized until the` y t n said terminals', and inea responsive to said:

-line terminals;

,said transmitters 'eing provide i with a circuit changing device arrangedfto I tor saidgcircuit` changing devices t and sitions thereof, and control in each-of said switches `ai"ranged yto tfr'gzivel 7 over and-make contact with' said terminals; y

ysets of positions, like trains of impulsesbb" circuit changing device for setting., id; brushes'within a particular-.groupe sa' ,i

4 80 switches arranged'to interconnect said line circuits, line terminals in`fsaidselectiiie,`

switches, the yterminalsfofa "group ,being over. and' make' contact` with 'said minals,

e ao actuated whilesaid impulse trans'i'nitters are l `being actuated, 'means forjsendiiiginipiilses g, V :whilefoperatingyand control means sald selective switches" responsive'in' one man@ other mannerf'to said impulses,

substations connected to Said'llines' each switches, ftheterminals of one' group lacing,,1,y

nals ofcther groups, a single'setofbruslies i.

and means controlled automatically byy Sai substation impulse transmitter for `detey i mining which ofl said groupsofgterizninals said brushes shall be directjed'to,`

6.In a telephone system," oups QM phone v-flines, `selectivey switches arranged,`

1- V f. ....ffDf-ff'gl' interconnect said-lines, 'impulse transmitters to control said switches, line terminals in said switches linked to said lines, the terminals leading to one group of lines being periodically interspersed between the terminals leading to other groups of lines, a single set of brushes in each of said switches arranged to'travel over and make contact with said terminals, and means controlled b said ,im-

ulse transmitters for automatica ly directing the brushes of said switches to a particular group of said line terminals.

7. In a telephone system, groups of telephone lines, multigroup selective switches arranged to interconnect said lines, impulse transmitters for controlling said switches, fixed terminals in said swatches linked to said telephone lines, the terminals of one 5,1m altipiani@` system,,'telephohaiiins,

i group being periodieall interspersed between the terminals of'ot er groups, a single Set of brushes in each of said switches arranged to travel over and make contact wlth l said terminals, means controlled by the operation of said impulse transmitter -in one manneror selecting a set iny a particular ygroup of said terminals, and means co-ntrolledby the operation of said impulse transmitter in another manner for' selecting a corresponding set of terminals'in another of said groups of lines.l

8. In a telephone system, groups of telephone lines, multi-group selective switches arranged to interconnect said lines` impulse transmitters for controlling said switches, fixed terminals in said switches linked to said telephone lines, the terminals of one` group being periodically interspersed between the terminals of other groups, a single set of brushes in each of said switches arranged to travel over and make contact with said terminals, means controlled by a single operation of said impulse transmitter in one mannerfor selecting a set in a particular group of said terminals, and means controlled by a single operation of said impulse transmitter in another manner for selecting a c rresponding set of terminals in another of said groups of lines.

9. In a telephone system, telephone lines arranged in groups, iniilti-group selective switches arranged to interconnect said lines, impulse transmitters lor controlling" said switches, fixed terminals in each of said switches linked'to Said telephone lilies, the terminals 01"' one group being periodically interspersed between the terminals ot' other groups, a single set ot' brushes iii each of said switches arranged to travel over and make contact with said terminals, said iinpulse transmitter being provided with a circuit changing device operable while being actuated to direct said brushes into association with one or another' of 'said groups of line terminals, and means controlled by said impulse transmitters While operating to di rect said brushes to a particular set of terminals in said selected group.

10. In a telephone system, groups of telephone lines, multigroup selective switches arrangedto interconnect said lines, impulse transmitters, Said switches being provided with a plurality of banks of fixed terminals and a set of brushes to travel over and make contact with said terminals, said impulse transmitter being arranged to operate from a plurality of sets of positions tov send the same train of impulses in corresponding positions in each of said sets of positions, a circuit changing device included in said iinpulse transmitter arranged to be dilerently actuated in each of said sets of positions, and means controlled by said circuit changing device for causing said brushes to be set in association with one or another of said `banks of terminals.

11. `In 'a tele hone system, groups of telephone lines, se ective switches -for serving a plurality of groups of lines each for interconnecting said lines, line terminals in said switches, the terminals of one group of lines being periodically interspersed between the terminals of other groups of lines, control circuits for said switches including a marginal relay, impulse transmitters for `setting said switches arranged to send a plurality of sets of impulses from a plurality of correspending sets of positions while operating, and also arranged to differently actua-te said marginal relay while being set in each of said different sets oir' positions, whereby said switches may be set onl aparticular setfof said terminals in a particular one ofsaid groups of line terminals.

In witness whereof, I hereunto subscribe ny name this 29th day of November A. D., 1 16.

`11`RANVK A. LUNDQUIST. 

